Paramagnetic resonance of Fe³⁺in kyanite

Abstract

The electron spin resonance spectra of Fe3+ ions in natural crystals of triclinic kyanite Al2SiO5 can be interpreted with a spin Hamiltonian with predominant crystal field terms 1/3DO20 and EO22. There are three strongly populated inequivalent sites with parameters | D | = 10.66, 21.4, 39 Gc/s; E/D = 0.055, 0.193, 0.044. A fourth Fe3+ site, and a fourth Cr3+ site, both weakly populated, have been detected. A discussion is given on the application of Fe3+ ions, in low symmetry crystal fields, for zero magnetic field maser use.